CLEVELAND (AP) — More than four decades after a 17-year-old girl about to start her senior year was reported missing and her body was buried in an unmarked grave in Cleveland, police have launched a murder investigation to find out who killed her alongside a river.

A process that began two years ago has led authorities to confirm that the teenager found outside at a park outside Cleveland in 1975 was Linda Pagano.

Her brother, Mike Pagano, said he “thought it was a dream” when he was told about two weeks ago that his sister’s body had been found.

“I thought this day would never come,” Pagano said at a news conference Thursday at the Cuyahoga County Medical Examiner’s Office. “I figured I’d die wondering.”

The Akron Beacon Journal first reported how Linda Pagano was identified.

She was reported missing by her stepfather around Labor Day 1974, a day or two after he had kicked her out of his apartment for returning late from a concert. Mike Pagano said his sister had been staying with the stepfather for the summer. Linda knew their stepfather was lonely after divorcing their mother, he said, and Linda was the favorite of his three stepchildren and bought her a car that summer.

Friends and family searched far and wide for Linda when she didn’t return to her mother’s home in nearby Springfield Township. People went door to door asking if they had seen her and put up flyers with her photo.

Cheryl Pagano, Linda’s sister, said she initially thought she would be found alive. Not long after, she said, when their mother and Linda’s friends hadn’t her heard from her, “I knew something happened to her and she was dead.”

Cleveland Metroparks Rangers Lt. Don Sylvis said Thursday that three teenagers walking in the woods in Strongsville in February 1975 found skeletal remains but no other evidence. The Cuyahoga County Coroner’s Office determined it was a woman in her early 20s who had died from a shotgun wound to the head and ruled her death a homicide. With no other leads to pursue, she was buried her in an unmarked grave at a Cleveland cemetery.

It’s now up to Metroparks detectives to find her killer. Detectives will begin by re-interviewing people they can find, Sylvis said.

Asked about the stepfather, who died in 1990, Sylvis said, “I think it would be safe to say he was a person of interest of some type but not a suspect. He was the last person to see her.”

The Beacon Journal has reported that the process of identifying her body began with genealogist Christina Scales finding a reference to the discovery of the remains. She contacted the Metroparks rangers, received information about the case and uploaded documents to Reddit. A forensic artist, Carl Koppelman, used a photo in the police file to create a sketch that he posted on Facebook. He then discovered that information about the remains had never been listed on a national database for missing persons.

An Akron police detective working on missing-persons cases typed Pagano’s name into the database and saw a potential match. Her body was exhumed, and her DNA was eventually matched with her siblings.

Cheryl Pagano said she wasn’t sure what to think when she learned that her sister’s body had been found.

“One minute you’re feeling good about it and the next you’re not feeling so good,” she said. “There’s no happy medium.”